#include <bits/stdc++.h>
using namespace std;

constexpr int mod = 998244353;

long long fac[200005], finv[200005], inv[200005];

void COMinit() {
    fac[0] = fac[1] = finv[0] = finv[1] = inv[1] = 1;
    for (int i = 2; i < 200005; i++) {
        fac[i] = fac[i - 1] * i % mod;
        inv[i] = mod - inv[mod % i] * (mod / i) % mod;
        finv[i] = finv[i - 1] * inv[i] % mod;
    }
}

long long COM(int n, int k){
    if (n < k) return 0;
    if (n < 0 || k < 0) return 0;
    return fac[n] * (finv[k] * finv[n - k] % mod) % mod;
}

long long choose(int n,int k) {
    if(n < 0 || k < 0) return 0;
    if(n == 0) return 1;
    return COM(n+k-1,k-1);
}

long long modpow(long long a,long long b) {
    long long ans = 1;
    while(b) {
        if(b & 1) {
            (ans *= a) %= mod;
        }
        (a *= a) %= mod;
        b /= 2;
    }
    return ans;
}

void mpl(int &x,int y) {
    x += y;
    if(x >= mod) x -= mod;
}

int main() {
    long long N;
    int M;
    cin >> N >> M;
    if(N >= M) {
        int ans = modpow(2,N);
        int res = 1;
        for(int i = 0; i < M; i++) {
            mpl(ans,mod-res);
            res = 1ll*res*((N-i)%mod)%mod;
            res = 1ll*res*modpow(i+1,mod-2)%mod;
        }
        cout << ans << endl;
    }
    else {
        cout << 0 << endl;
    }
}